The very first medieval knights rode into battle in mail [also known as chain mail].  This was a flexible armor that could bend easily because it was made of linked iron rings.  The armor was made so it would fit the knight well, g the head and making a very heavy tunic over the body.  But mail didn't offer complete protection, it could still be pierced by arrows.  In the late 1200's knights started to cover their knees with steel plates, and in the next hundred years, a lot more plates were added.  By the 1400's, the knight's body was covered in plates of steel.  These were all fitted well and made of sections joined by rivets and straps of leather.  It wouldn't have been simple to fight in plate armor weighing about 50 pounds.  However
, it was light enough for a knight to move pretty fast and to get up if he fell from his horse.
 
 

A Coat Of Mail

In the 1100's, when a knight leaves for war, he would be wearing mail armor.  The knight's long tunic is called a hauberk.  It came down to the knees, where it was cut so the knight could mount his horse easier.  The hood protecting the neck below the helmet is called a coif.  Underneath the mail, the knight wears a padded garment called an aketon.  This word comes from the Arabic word al-qutum which means cotton.
 
 

Helmets

In the 1000's and 1100's, most knights wore a cone shaped helmet with a nosebar, or nosel.  At the end of the 1100's, guard for the whole face were made, then came the helm, [which covered the head and face completely].  The basinet of the 1300's included a visor, which could be raised and lowered.  The fanciest helmets of them all were designed especially for tournaments.
 
 

The Shield

A knight's shield protected him from showers of arrows and can deal with fierce blows by extremely strong weapons.  The design changed over the years from a long kite looking shield of the Norman's to the smaller triangular shape of the 1300's, made of leather covered wood.  Plate armor made shields unnecessary.